Chinese irrigation tunnel project in Xinjiang hits snag: too much water
The project aims to open desert areas for development, but experts say it could dilute the Uyghur population.
A secretive 500-kilometer-long irrigation project China is building to divert snowmelt from the Altay Mountains to desert areas in its restive Xinjiang region has developed a too-much-of-a-good-thing problem. Workers keep tapping into gushing flows of groundwater that have slowed construction to a crawl.
Based in part on the 2,000-year-old karez (well) system designed by Uyghurs in Turpan (in Chinese, Tulufan), China began constructing the 514-kilometer-long (320-mile-long) project years ago in what is reportedly the longest underground irrigation canal system in the world.
The project comprises three deeply dug tunnels, the longest of which is the 280-kilometer-long (174-mile-long) Kashuang Tunnel — twice as long as the Delaware Aqueduct, the main channel supplying water to New York City.
Despite the project’s size, China’s official media has yet to report on the irrigation network, which has given rise to a fair amount of speculation about what purpose the water line will ultimately serve, particularly as it is being built at a time of well-documented persecution against Uyghur Muslims who live in the area.
A few details first appeared in a scientific report by Deng Mingjiang, a Chinese academic at the Chinese Academy of Engineering, and his colleagues in February 2018.
A second report he wrote for the Chinese peer-reviewed journal Tunnel Construction in November 2021 discussed the geological issues facing engineers.
“The high level of groundwater has consistently led to flooding and had adverse effects on the construction plans,” according to the authors of the paper recently published in the Journal of Tunnel Construction.
Workers have been hit by strong streams of water, forcing them to flee the site. The problem is having a serious detrimental impact on construction, according to the Tunnel Construction report.
The tunnel excavation rate has dropped to barely 200 meters (656 feet) per month, half the average rate in arid regions such as the Xinjiang, the journal article states. About 60 percent of the project had been completed as of June 2021, with experts believing that the ongoing flooding might lead to more significant delays in construction.
A Chinese team of engineers is now attempting to solve the problem. In one effort, they built an earthquake detector in the tunnel to anticipate the water flow on their excavation route so as to prepare for flooding, the report says.
In addition to the problems caused by the complex geological conditions of the area, half of the project’s road calculation estimates, which were based on geological assessments, have turned out to be incorrect, according to the report.
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